<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <script src="./jq-3.6.0.js"></script>
</head>

<body>
    <button>点击一下</button>
</body>
<script>
    var bn = document.querySelector('button');
    bn.onclick = function() {
        console.log(this);
        //把元素对象转换jq对象
        var n1 = $(bn);
        console.log(n1);
        //把jq对象转换成元素对象的两种方式
        console.log(n1[0]);
        console.log(n1.get(0));
    }
</script>

</html>